Fabrication Of Ultra Thick Ferromagnetic Structures In Silicon

A novel fabrication process has been developed to create ultra thick ferromagnetic structures in silicon. The structures are fabricated by electroforming NiFe into silicon templates patterned with deep reactive ion etching(DRIE). Thin films are deposited into photoresist molds for characterization of an electroplating cell. Results show that electroplated films with a saturation induction above 1.6 tesla and compositions of approximately 50/50 NiFe can be obtained through agitation of the electrolyte. Scanning electron microscopy (SEM) images show that NiFe structures embedded in a 500πm thick silicon wafer are realized and the roughening of the mold sidewalls during the DRIE aids in adhesion of the NiFe to the silicon.